I certainly appreciate the time you put into this. I have always agreed that miles would be the intuitive answer; however, I am a scientist writing scientific professional opinions for clients, and as we both agree, miles is not factually correct when dealing with a fraction of a mile. I will admit I have written it both ways, but had not decided which way was satisfying to me as a writer.
I too spent way too much time researching this prior to posting here, and I should have mentioned that to save you some time. I sincerely apologize.
Unfortunately, abbreviation is out of the question, as we do not abbreviate anything in our professional reports, including Street, Boulevard,... well, you get the idea.
Thanks again for your unpaid effort. I believe in karma (or the doctrine of inevitable consequence!)